Modify BufferGetPage() to prepare for "snapshot too old" feature

This patch is a no-op patch which is intended to reduce the chances
of failures of omission once the functional part of the "snapshot
too old" patch goes in.  It adds parameters for snapshot, relation,
and an enum to specify whether the snapshot age check needs to be
done for the page at this point.  This initial patch passes NULL
for the first two new parameters and BGP_NO_SNAPSHOT_TEST for the
third.  The follow-on patch will change the places where the test
needs to be made.

1 files changed, 27 insertions, 23 deletions

diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c
index 01a4e0f2528..b5fc2663f03 100644
--- a/src/backend/access/spgist/spgxlog.c
+++ b/src/backend/access/spgist/spgxlog.c
@@ -79,7 +79,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 
 	buffer = XLogInitBufferForRedo(record, 0);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_METAPAGE_BLKNO);
-	page = (Page) BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	SpGistInitMetapage(page);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
@@ -88,7 +88,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 	buffer = XLogInitBufferForRedo(record, 1);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_ROOT_BLKNO);
 	SpGistInitBuffer(buffer, SPGIST_LEAF);
-	page = (Page) BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
@@ -96,7 +96,7 @@ spgRedoCreateIndex(XLogReaderState *record)
 	buffer = XLogInitBufferForRedo(record, 2);
 	Assert(BufferGetBlockNumber(buffer) == SPGIST_NULL_BLKNO);
 	SpGistInitBuffer(buffer, SPGIST_LEAF | SPGIST_NULLS);
-	page = (Page) BufferGetPage(buffer);
+	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 	PageSetLSN(page, lsn);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
@@ -136,7 +136,7 @@ spgRedoAddLeaf(XLogReaderState *record)
 
 	if (action == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		/* insert new tuple */
 		if (xldata->offnumLeaf != xldata->offnumHeadLeaf)
@@ -183,7 +183,7 @@ spgRedoAddLeaf(XLogReaderState *record)
 
 			XLogRecGetBlockTag(record, 0, NULL, NULL, &blknoLeaf);
 
-			page = BufferGetPage(buffer);
+			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			tuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -249,7 +249,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	{
 		int			i;
 
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		for (i = 0; i < nInsert; i++)
 		{
@@ -278,7 +278,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	/* Delete tuples from the source page, inserting a redirection pointer */
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		spgPageIndexMultiDelete(&state, page, toDelete, xldata->nMoves,
 						state.isBuild ? SPGIST_PLACEHOLDER : SPGIST_REDIRECT,
@@ -297,7 +297,7 @@ spgRedoMoveLeafs(XLogReaderState *record)
 	{
 		SpGistInnerTuple tuple;
 
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		tuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -338,7 +338,7 @@ spgRedoAddNode(XLogReaderState *record)
 		Assert(xldata->parentBlk == -1);
 		if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer);
+			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			PageIndexTupleDelete(page, xldata->offnum);
 			if (PageAddItem(page, (Item) innerTuple, innerTupleHdr.size,
@@ -381,7 +381,7 @@ spgRedoAddNode(XLogReaderState *record)
 			action = XLogReadBufferForRedo(record, 1, &buffer);
 		if (action == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer);
+			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			addOrReplaceTuple(page, (Item) innerTuple,
 							  innerTupleHdr.size, xldata->offnumNew);
@@ -410,7 +410,7 @@ spgRedoAddNode(XLogReaderState *record)
 		{
 			SpGistDeadTuple dt;
 
-			page = BufferGetPage(buffer);
+			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			if (state.isBuild)
 				dt = spgFormDeadTuple(&state, SPGIST_PLACEHOLDER,
@@ -462,7 +462,7 @@ spgRedoAddNode(XLogReaderState *record)
 			{
 				SpGistInnerTuple parentTuple;
 
-				page = BufferGetPage(buffer);
+				page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 				parentTuple = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -522,7 +522,7 @@ spgRedoSplitTuple(XLogReaderState *record)
 			action = XLogReadBufferForRedo(record, 1, &buffer);
 		if (action == BLK_NEEDS_REDO)
 		{
-			page = BufferGetPage(buffer);
+			page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			addOrReplaceTuple(page, (Item) postfixTuple,
 							  postfixTupleHdr.size, xldata->offnumPostfix);
@@ -537,7 +537,7 @@ spgRedoSplitTuple(XLogReaderState *record)
 	/* now handle the original page */
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		PageIndexTupleDelete(page, xldata->offnumPrefix);
 		if (PageAddItem(page, (Item) prefixTuple, prefixTupleHdr.size,
@@ -608,7 +608,7 @@ spgRedoPickSplit(XLogReaderState *record)
 	{
 		/* just re-init the source page */
 		srcBuffer = XLogInitBufferForRedo(record, 0);
-		srcPage = (Page) BufferGetPage(srcBuffer);
+		srcPage = BufferGetPage(srcBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		SpGistInitBuffer(srcBuffer,
 					 SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
@@ -625,7 +625,7 @@ spgRedoPickSplit(XLogReaderState *record)
 		srcPage = NULL;
 		if (XLogReadBufferForRedo(record, 0, &srcBuffer) == BLK_NEEDS_REDO)
 		{
-			srcPage = BufferGetPage(srcBuffer);
+			srcPage = BufferGetPage(srcBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 			/*
 			 * We have it a bit easier here than in doPickSplit(), because we
@@ -661,7 +661,8 @@ spgRedoPickSplit(XLogReaderState *record)
 	{
 		/* just re-init the dest page */
 		destBuffer = XLogInitBufferForRedo(record, 1);
-		destPage = (Page) BufferGetPage(destBuffer);
+		destPage = BufferGetPage(destBuffer, NULL, NULL,
+								 BGP_NO_SNAPSHOT_TEST);
 
 		SpGistInitBuffer(destBuffer,
 					 SPGIST_LEAF | (xldata->storesNulls ? SPGIST_NULLS : 0));
@@ -674,7 +675,8 @@ spgRedoPickSplit(XLogReaderState *record)
 		 * full-page-image case, but for safety let's hold it till later.
 		 */
 		if (XLogReadBufferForRedo(record, 1, &destBuffer) == BLK_NEEDS_REDO)
-			destPage = (Page) BufferGetPage(destBuffer);
+			destPage = BufferGetPage(destBuffer, NULL, NULL,
+									 BGP_NO_SNAPSHOT_TEST);
 		else
 			destPage = NULL;	/* don't do any page updates */
 	}
@@ -722,7 +724,7 @@ spgRedoPickSplit(XLogReaderState *record)
 
 	if (action == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(innerBuffer);
+		page = BufferGetPage(innerBuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		addOrReplaceTuple(page, (Item) innerTuple, innerTupleHdr.size,
 						  xldata->offnumInner);
@@ -762,7 +764,8 @@ spgRedoPickSplit(XLogReaderState *record)
 		{
 			SpGistInnerTuple parent;
 
-			page = BufferGetPage(parentBuffer);
+			page = BufferGetPage(parentBuffer, NULL, NULL,
+								 BGP_NO_SNAPSHOT_TEST);
 
 			parent = (SpGistInnerTuple) PageGetItem(page,
 								  PageGetItemId(page, xldata->offnumParent));
@@ -813,7 +816,7 @@ spgRedoVacuumLeaf(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		spgPageIndexMultiDelete(&state, page,
 								toDead, xldata->nDead,
@@ -876,7 +879,7 @@ spgRedoVacuumRoot(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		page = BufferGetPage(buffer);
+		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
 
 		/* The tuple numbers are in order */
 		PageIndexMultiDelete(page, toDelete, xldata->nDelete);
@@ -917,7 +920,8 @@ spgRedoVacuumRedirect(XLogReaderState *record)
 
 	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
 	{
-		Page		page = BufferGetPage(buffer);
+		Page		page = BufferGetPage(buffer, NULL, NULL,
+										 BGP_NO_SNAPSHOT_TEST);
 		SpGistPageOpaque opaque = SpGistPageGetOpaque(page);
 		int			i;